Just go to:
Local Disk/Program Files/Steam/ Steamapps / Common/ Call of Duty Modern Warfare 2/ Players and delete all stat files
Now go to:
Local Disk/Program Files/Steam/Userdata
and delete the folder

Things to do:
[] - done, [] - need to complete
Make a mod for mw2 []
Make a working mod for mw2 []
Hack PB []
Make a bot for RS []
Reach 100 posts []
Make an mw2 clan []
Get a 150 killstreak on mw2 []
Bot a lvl 99 on Runescape []